From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF769C43381 for ; Mon, 1 Apr 2019 07:39:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A009206B8 for ; Mon, 1 Apr 2019 07:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731995AbfDAHjQ (ORCPT ); Mon, 1 Apr 2019 03:39:16 -0400 Received: from foss.arm.com ([217.140.101.70]:56676 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731769AbfDAHjP (ORCPT ); Mon, 1 Apr 2019 03:39:15 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C641B374; Mon, 1 Apr 2019 00:39:14 -0700 (PDT) Received: from blommer (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E1CDC3F690; Mon, 1 Apr 2019 00:39:12 -0700 (PDT) Date: Mon, 1 Apr 2019 08:39:02 +0100 From: Mark Rutland To: Matteo Croce Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon Subject: Re: [PATCH] arm64/vdso: don't leak kernel addresses Message-ID: <20190401073901.wun6lnthvbvq6gd4@blommer> References: <20190330184638.16219-1-mcroce@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190330184638.16219-1-mcroce@redhat.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 30, 2019 at 07:46:38PM +0100, Matteo Croce wrote: > Since commit ad67b74d2469d9b8 ("printk: hash addresses printed with %p"), > two obfuscated kernel pointer are printed at every boot: > > vdso: 2 pages (1 code @ (____ptrval____), 1 data @ (____ptrval____)) > > Remove the addresses from the print, which turns into a more discrete: > > vdso: 2 pages (1 code, 1 data) > > Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") > Signed-off-by: Matteo Croce > --- > arch/arm64/kernel/vdso.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c > index 2d419006ad43..fdfee0ef5bc5 100644 > --- a/arch/arm64/kernel/vdso.c > +++ b/arch/arm64/kernel/vdso.c > @@ -146,8 +146,8 @@ static int __init vdso_init(void) > } > > vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; > - pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n", > - vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data); > + pr_info("vdso: %ld pages (%ld code, %ld data)\n", > + vdso_pages + 1, vdso_pages, 1L); It's probably better to drop this pr_info() entirely. The number of data and code pages hasn't changed since this was upstreamed, and the pointers were the useful part for debugging. If you respin this to delete the pr_info() entirely, then feel free to add: Acked-by: Mark Rutland Mark.